D&D 5E Share Your Meanest, Most Dastardly Trap

[Lidgar]

The party sees a long passageway disappearing into darkness. The walls are covered with plaster with frescoes of slaves hauling piles of treasure and other goods towards the far end of the hall. The floor is covered in steel plates.

After 100', the party encounters magical darkness. The passage continues, but gradually begins sloping down (DC 15 perception to notice the slope).

After another 100', the slope becomes much steeper. At the same location, the steel-plated floor is covered in grease. DC 18 Dexterity save to avoid falling down and sliding down the passage in complete darkness.

Another 50' down the "slide," a razor-thin, 20-foot long blade of steel is mounted in the middle of the floor (8d12 slashing damage, DC 18 Dex save for half).

The bottom of the slide becomes a vertical shaft, which is another 100' deep (10d6 damage). At the bottom of the pit is a collection of skeletons that have been neatly cleaved in half.

 

[Shiroiken]

The best one I remember from 2E was from an adventure called Tower, Temple, and Tomb (I think). There was a hall with several doors leading from it, all locked and trapped, each in it's own alcove. Failing to disarm the trap triggered it, as did just attempting to push open the door. Once triggered, the hall filled with flames, flying spears and darts, plus maybe some acid. The ONLY space that was safe... was the one directly in front of the door that was triggered. Thus the usually hapless thief (that was universally sent forward to deal with these things, and often slain in the process) was the only one to escape unscathed.

A friend did something cruel in a high level 3E game, where he stole the idea of the movie Labyrinth (which was one of the player's favorite movie). A hallway had faces carved on it that called out Doom and Death to any who go farther. If you walked through the door at the end of the hall you had to make a Con save (DC: 30 IIRC) or die. The player who loved the movie suspected something like this, and threw another PC through the portal to prove it was lethal. It turns out there was a secret door behind one of the faces or something.

My personal best was painted glass over an acid vat in 1E. Fairly simple, because if you didn't suspect a trap (and players had to describe what they suspected), you'd just walk over it and if you weighed over 150 lbs (with stuff), you broke the glass and fell in. Save vs. Death, taking 20d6 damage if you succeeded. The floor wasn't often checked, unless it was described oddly, but the paint gave it the impression of normalcy, except to the most paranoid.

 

[Caliban]

I've always had a bit of a problem with some of the more bizarre or grandiose traps in D&D. Namely:

A) Much of the time they don't seem to serve any real purpose, or would hinder the inhabitants of the dungeon even more than the adventurers.
B) Many of them seem to use incredibly powerful magics that aren't used anywhere else, which seems like a major continuity error.
C) Even the ones that use more commonly available effects would cost so much to create that they would bankrupt whatever person or organization created it.

Still, they are a staple D&D trope.

 

[ccs]

It was a simple trap to escape from....

The party was exploring a ruined castle. They came upon a room (about 30'w x 50'L) that looked like it was a reception hall of some sort. An open door at the opposite end. Scattered about the room were dozens of long dead people (now mostly skeletal remains) who looked as if they'd been having a cocktail party or some such.

Party enters & begins searching about. The spirits rise & continue their reception, chatting amongst themselves. Noticing the PCs, several of the spirits engage them in conversation. Very interested in who the PCs are, where there from, etc etc etc. Backstory stuff.

To leave the ghostly reception, all the PCs have to do is RP with the "ghosts". Tell various of their backstories. Or lie about those bits.... Then pass a rather simple DC Cha check. Then walk out the far door.
Each true thing shared automatically reduced the DC by 1. Each lie first required a DC15 Bluff check before the bonus could be claimed.
That is the ONLY way out of this room. RP with the ghosts, walk out the far door. Nothing else (well, maybe a Wish. But they were many lvs away from that option)
Each attempt required new details to be provided/lied about.
Failure resulted in the character being stuck in the room for another hour before another attempt could be made.
If you existed the room & came back in? You had to RP with the ghosts again & reveal/lie about new details.
And this was not an area where you could rest.


3 of the PCs "escaped" with ease. In fact they re-entered & exited the room several times showing off how it was done & revealing loot they'd found while exploring the rest of the castle.
The other two? They spent many many many hours of game-time trapped in the ghostly tea party. They burned every spell they had, they tried to destroy things, & they damned near died of exhaustion before finally escaping.
One guy kept attempting to lie - & failing. He didn't want to share anything "true" about his character. Eventually though he just told some truths to escape as his dice just wouldn't cooperate. It was share or become a ghost himself....
The other one just pretty much refused to RP. He was bound & determined that he'd find some other way to escape. As he wasn't the DM, he was quite mistaken. Eventually before the session ended he told some lies that were believed & walked out the far door.

How simple of a trap is this? All you have to do to escape is BS. What gamer can't do that?

To be fair though this trap WAS aimed at the two players who fell victim to it. Neither ever had any details of their characters beyond stats/name/race/gender & the group had grown weary of that & they were informed that the next time they made characters in such a manner it'd matter.

 

[was]

...there was a round room with a pedestal in the middle. On the pedestal was a massive gem. The gem was grabbed by the rogue who failed to disarm the magical trap, causing the wall of force (floor) to disappear.

...the pedestal sat on a narrow, round column. Everyone, except the rogue, fell 50' onto spikes. Water then began to fill the room.

....there was hidden disarm switch for the water 1/2 way up the column. it took a while to find. the rogue actually had to dive under water to disarm it.

 

[Caliban]

I haven't used it yet, but I once designed a trap that used a combination of Pits, Anti-Magic fields from the top of the pit to 5' from the bottom, then Teleport Circles that activated after you hit the bottom, and Reverse Gravity spells to batter you and then eject you from the dungeon at high speed via a concealed tunnel. Then you had to deal with the wildlife wherever you landed.

It had all the flaws I listed above, but it seemed like a good idea at the time. A very tidy dungeon.

 

[nswanson27]

A room full of flammable alcohol and a party member dumb enough to cast a fire spell.

 

[Imaculata]

This is a trap + boss battle that I sprung on my players during my 3.5 pirate campaign.

The players enter a large, deep, underground chamber. Immediately a heavy stone door drops behind them, locking them inside. An old stone bridge with no railings, leads to a central platform with an old tomb, that radiates with protective magic. The platform is supported by one stone pillar, and a few ruined walls remain of what was once a crypt. Along the walls of the dark cave are three waterfalls, and below the platform is a large pool of water.

What the players do not know, is that behind the waterfalls there's an ambush of aquatic spiders. The spiders can shoot their webs though the waterfalls, and if they succeed to hit a PC, they will attempt to pull the PC off the platform. Down below the water the spiders have built a devious trap; dozens of webs, in which any PC will get entangled as soon as they hit the water. The spiders themselves have no trouble staying underwater, since they carry air bubbles on their backside, but the PC's are at risk of drowning. The spiders' underwater nests are also filled with the corpses of their old victims, but the players may be able to gather some valuables from these nests.

There's also a big mommy spider, who's main objective is to guard the tomb. She has no trouble moving over the feeble bridge, towards the platform. The players are caught between a rock and a hard place.

The players can escape the room through an underwater passage.

 

[transtemporal]

Meteor trap. Triggered by annoying PC. A meteor hits you, no save, you're dead.

 

[MarkB]

I did come up with a nasty one some time ago - a very tall cylindrical room with a steeply sloped floor and ceiling. The half of the room opposite the entrance is covered by a Reverse Gravity effect. Anyone who crosses the room falls up to the ceiling, rolls up the slope out of the field, falls down to the ground, rolls down the slope into the field, and repeat, in an endless cycle of falling damage.

Not too difficult to detect - the field results in a small but constant circulating airflow, and simply throwing an object into the room will reveal its nature - but very nasty for the unwary. An upgraded version would trigger the field and tilt the floor and ceiling only after someone enters the room.